More air quality improvements anticipated for wood stoves

DOVER — It’s the picture of a New England winter, being curled up with a cup of hot cocoa while the fire blazes and the storm rages outside.

Wood is a renewable resource and provides an affordable solution for heating a home, so it is no surprise that many New Hampshire residents choose to heat with wood stoves.

“It utilizes wood that otherwise wouldn’t have a market, which therefore improves the forest by allowing better trees to grow,” said Sarah Smith, a forestry resource specialist with the UNH Cooperative Extention. “It is also a local fuel source, so even if you are buying it from someone else the money is staying local.”

However, despite the benefits, a number of state and national agencies are now saying that wood burning is not always as ideal as people expect. In fact, burning wood to heat a home can lead to environmental, safety and health problems if it is not done responsibly.

“With wood stoves and wood smoke in general, there are a number of things that are present that are volatile organic compounds,” said Dennis Pinski, manager of the Environmental Health Program at the N.H. Department of Environmental Services. “There is a potential for a number of harmful effects when people breathe those in.”

The effect of wood-burning devices can be drastic. Although many people enjoy the smell of a fire, wood smoke contains over 100 different chemical compounds, some of which are harmful or carcinogenic. This can lead to irritated eyes or breathing problems, and become a (n even) bigger environmental issue when many people in one area use wood-burning devices, as is the case in New Hampshire.

Researchers found more than 80 percent of the particle matter in the air in regions of New Hampshire is related to wood burning stoves. Particle levels are directly correlated to the times that people are using their stoves, Pinski said.

“The levels are stable in the morning and through day, but when people come home at end of day and fire up their stoves, you see a rise throughout the late afternoon and evening.”

During the winter when cool, stagnant air limits movement, the issue is compounded.

The impact of wood stoves on air quality is so significant that wood burning devices have been regulated by the Environmental Protection Agency (EPA) under the Clean Air Act since 1990. In January, the EPA revised its standards, requiring all new stoves manufactured or sold after this year to meet more rigorous standards. On Feb. 26 from 9 a.m. to 7 p.m. the EPA will hold a public hearing on the new regulations at the EPA New England Regional Offices, 5 Post Office Square, Suite 100, in Boston.

Luckily, there are steps that New Hampshire consumers can take to make burning wood a more environmentally friendly heating option. EPA-certified stoves reduce smoke emissions and burn more efficiently, cutting back on environmental concerns while saving money.

When a stove burns wood more thoroughly it reduces the number of particles and harmful gasses that are released into the air. EPA-certified stoves are designed to promote secondary combustion, which burns off chemicals and gasses before they leave the stove, making the smoke cleaner. Pellet stoves are another high-efficiency option because the smaller pieces of wood are more exposed to burning and the pellets are fed into the stove at a controlled rate. Both of these factors contribute to a more complete combustion.

“There had been an attempt over past few years to move from older, inefficient units that cause a lot of pollution to newer burning units that run more efficiently and give off less pollution,” Pinkski said. “The new units are better for the environment and for people’s health, both within the home and within a community.”

However, many people in New Hampshire still use stoves that were manufactured before the introduction of EPA protocols. Further, older stoves are more expensive to run because they burn more wood.

In addition, some new stove purchases qualify for tax breaks as renewable and efficient energy sources. Some towns allow a property tax exemption equal to the value of the system. There is also a state tax credit of up to $6,000 for qualified systems that provide up to 75 percent of a home’s heating needs. To learn more about tax credits, visit www.dsireusa.org.

It is also important for consumers to burn the correct fuel in their stoves. According to the EPA, the best wood to burn is hardwood that has been seasoned for six to eight months before use. Seasoning the wood allows the moisture content to drop. Whereas fresh-cut wood has a 50 percent moisture content, the ideal content for burning is around 20 percent. This produces a more even burn and helps prevent flammable buildup within stoves and chimneys. It is also a more effective way of heating, since the energy of the burn is being used to generate heat rather than to evaporate moisture in the wood. Chopping wood into smaller pieces and maintaining a high temperature also increase a stove’s efficiency. A healthy fire should be burning brightly with little visible smoke.

Of course, another area of concern with wood stoves is fire-safety. To keep stoves and fireplaces safe, they must be installed correctly and maintained regularly.

“Like any other machine, solid fuel burning appliances require regular maintenance,” said New Hampshire State Fire Marshal J. William Degnan.

Over the past 20 years, the leading cause of structure fires in New Hampshire has been solid fuel burning appliances, including chimneys, wood stoves and outdoor wood boilers. Although there are regulations in place about how these devices need to be installed and maintained, many fire investigations show that homeowners are not following the protocols.

“The bottom line is that we want people to be safe,” Degnan said. “Homeowners must do whatever is necessary to ensure their own safety. Checking their appliances and chimneys is just as important as checking your smoke detector and buckling your seat belt.”

For more information on burning safety, visit www.epa.gov/burnwise or www.extension.unh.edu/Energy/WoodHeat